Multi-ply container

ABSTRACT

A multi-ply container desirably of paperboard panels laminated together, has a corner construction comprising facing unattached end edges of a ply covered by an integral hinge connection between wall panels of another ply thereby eliminating a socalled manufacturer&#39;&#39;s joint. The corner construction and plurality of laminated plies provide bulge resistance rendering the container particularly advantageous for the packaging of flowable products such as synthetic rubber blocks.

[72] inventors Billy J. Muskopf Houston; Arthur T. Edwards, III. Dallas,Tex. [21] Appl No, 811,553 [22] Filed Mar. 28, 1969 [45] Patented Feb.2, 1971 [73] Assignee Crown Zellerbach Corporation San Francisco, Calif.a corporation of Nevada [54] MULTl-PLY CONTAINER 15 Claims, 17 DrawingFigs.

[52] US. Cl .1 229/14, 229/23 [51] Int. Cl B65d 25/14, 865d 5/56 [50]Field ofSearch 93/36; 229/14C, B1, DL, BW, 23B

[56] References Cited UNITED STATES PATENTS 1,121,947 12/1914 Surmann .6229/23 1,136,479 4/1915 Motz .1 229/14(BW) 2,208,268 J/l940 Snyder eta1. 229/23(B) 2,634,038 4/1953 George et a1. 229/14C 2,836,338 5/1950Daniels A. 2.29/14C 3,007,622 11/1961 George A .1 229/23B 3,145,9008/1964 Franklin l. 229/14C 3,146,932 9/1964 Mayer 229/14C PrimaryExaminer-Davis T. Moorhead Attorneys-Stanley Bialos, Corwin R. Hortonand William K.

Quarles PATENTED FEB 2|97| 3,559,867

sum 3 (IF 3 MULTl-PLY CONTAINER BACKGROUND OF THE INVENTION As isdisclosed in the US. Pat. to George et al.. No. 2,634,038, dated Apr. 7,I953. certain types of materials have inherent cold flow characteristicsafter being packaged in containers. For example, synthetic rubber has atendency to flow and spread out laterally exerting great pressureagainst the walls of the container. The container disclosed in suchpatent is of such character as to provide strength for withstanding suchlateral pressure, and comprises a plurality of telescoped sleeves ofvarying heights providing increasing thickness of the container wallsfrom the top to the bottom. Each sleeve is a continuous strip of wallpanels secured together at their end edges by a so-called manufacturersjoint, such as tape, which increases manufacturing costs in theapplication thereof.

SUMMARY AND OBJECTS Summarizing the invention hereof, an improvedcontainer is provided. Although it is particularly adapted for shippingand storing material, such as synthetic rubber which has theaforementioned cold flow characteristics and hence exerts great pressureagainst the container walls, it may be employed for the packaging ofother types of material which require a container of great strength. Thecontainer is desirably made of a plurality of plies of paperboard,advantageously so-called double wall corrugated paperboard.

The respective plies have wall panels which are adhesively laminated toeach other to form container walls of multi-ply substantially uniformthickness throughout. The plies are so arranged that so-calledmanufacturers joints such as corner tape, stitching or glue flaps arenot required to fasten end edges of panels together, as the panels ofthe plies provide at least an integral corner construction at each ofthe upright corners of the container. Advantageously, the containerwalls are of at least three-ply thickness with each upright corner of atleast two-ply thickness, which provide not only bulge resistance butalso marked stacking strength.

Also, at least one of the plies advantageously comprises a plurality ofpads; each pad having upright end edges and wall panels integrallyconnected along an upright hinge connection line positioned at anupright comer of the container. The end facing edges of adjacent padsare adjacent to but spaced apart at another corner, being free ofattachment whereby a gap is provided between such edges; and the spacebetween these facing edges is closed by an integral corner of acontiguous ply.

A special method is provided for forming the container from a collapsedstate of the plies, comprising adhesively uniting strips having wallpanels which form an inner ply and an intermediate ply, and adhesivelyuniting pads to the outer faces of the intermediate ply; each pad beingcomposed of wall panels integrally connected together along a cornerforming hinge connection line. The pads are so positioned that a hingeconnection line thereof is at a comer of the container and the endsthereof adjacent to but unsecured to each other at another comer of thecontainer.

From the preceding, it is seen that the invention has as its objectsamong others, the provision of an improved multi-ply containerconstruction having walls of substantially uniform thickness throughoutand in which the manufacturers joint commonly employed for securing endsof panels together at an upright comer of the container, is notrequired, which has great strength including stacking strength, and isof economical and simple construction, and-the provision of an improvedmethod for forming such container. Other objects of the invention willbecome apparent from the following more detailed description andaccompanying drawings in which:

DESCRIPTION OF FIGURES FIG. 1 is a plan view of a paperboard blankforming the inner liner of one embodiment of the invention;

FIG 2 is a transverse fragmentary cross-sectional view on an enlargedscale taken in a plane indicated by line 2-2 in FIG.

FIG. 3 is a plan view of an L-shaped reinforcing pad;

FIG. 4 is an exploded isometric view illustrating the relationship ofvarious parts of the container;

FIG. 5 is an elevational view of the container looking in the directionof arrow 5 in FIG. 6;

FIG. 6 is an enlarged horizontal cross section taken in a planeindicated by line 6-6 in FIG. 5;

FIG. 7 is a cross-sectional exploded view illustrating the relationshipof certain of the parts in the method of assembling the container;

FIG. 8 is a similar view illustrating the parts of FIG. 7 after theyhave been collapsed to another position, and illustrating therelationship of pads which form an outer ply;

FIG. 9 is a plan view on a reduced scale of a blank which forms anintermediate ply in another embodiment of the invention;

FIG. 10 is a plan view of a blank which forms the inner ply of suchembodiment;

FIG. 11 is a similar view of L-shaped pads which from an outer ply;

FIG. 12 is a schematic end elevational exploded view illustrating stepsin the method of assembling such embodiment;

FIG. 13 is a similar view illustrating further steps;

FIG. 14 is an enlarged horizontal cross section of the embodiment formedby the blanks of FIGS. 9 through 11;

FIG. 15 is a schematic view of an additional embodiment illustrating therelationship of inner and intermediate plies of a container of hexagonalhorizontal cross section;

FIG. 16 is a similar view illustrating the relationship of the outer plyto the remaining plies, and;'

FIG. 17 is an enlarged horizontal cross section of the container.

FIGS. 1 through 8 disclose an embodiment of the invention in which thecontainer has four upright walls and is rectangular in cross section;the walls being formed of three plies and are of uniform thicknessthroughout. Desirably the respective plies are of double wall corrugatedpaperboard, although solid paperboard of any other suitable type ofstrong sheet may be employed.

An inner ply 2 of the container comprises a continuous strip ofintegrally connected wall panels 3, 4, 6, 7 and 8 as can be seen fromFIG. 1, which are integrally hinged together along respective hingeconnection lines 11. End panels 3 and 8 of the strip are not full wallpanels but in the setup container which is rectangular in cross section,end edges 12 of these end panels face each other, being unattached toeach other but in substantial abutment to form substantially an abutmentjoint 13. Bottom closure flaps 16 are hingedly connected to the loweredge of inner ply 2 to form a bottom closure in the setup container. Theblank from which inner ply 2 is formed is known in the trade as a halfslotted container (I-ISC) blank.

Adhesively bonded to the outer face of inner ply 2 is a plurality ofL-shaped pads 17 which provide an intermediate ply of the container;each pad being composed of a continuous strip of wall panels 18integrally hingedly connected along an upright hinge connection line 19positioned substantially in alignment with an upright corner A of thecontainer. Each panel 18 is substantially a full wall panel, being ofsuch length that its end edge 21 is located closely adjacent anothercorner B. The adjacent facing edges 21 of adjacent panels 18 are alsounsecured together with a space or gap 21' existing between such facingedges 21 of adjacent pads. From FIG. 6 it will be noted that theabutment joint 13 of inner ply 2 is covered or closed by a panel 18 of apad 17.

A pair of L-shaped pads 22, each pad being similar to an intermediatepad 17, forms an outer ply of the container and is adhesively bonded toouter faces of pads 17 with the upright integral hinge connection line23 of each pad 22 overlying the space 21 at a corner between theadjacent edges 21 of intermediate pads 17. As with respect to edges 21of intermediate pads 17 the upright end edges 24 of adjacent outer pads22 form a gap 24 at the comer A defined by an integral hinge connectionof an intermediate pad 17.

From the preceding and as can be seen from FIG. 6, the container wallsare all of uniform thickness, and comprise three plies laminatedtogether by adhesive. Each upright corner of the container is of two-plythickness making for strength even though spaces 21' and 24' are formedbetween the free or facing unsecured edges of adjacent pads. Also, ineach instance corner spaces 21' and 24' are covered or closed by anintegral corner hinge connection of a contiguous ply.

Stitching or glue flaps, or tape are not required to secure corners ofthe respective plies together, thus making for manufacturing economy,and for improved strength and quality. Although abutment joint 13 ofinner ply 2 is located between adjacent corners of the container, itcould also be formed at any corner instead but then in the embodimentthus far described, there would only be one-ply thickness at one cornerand two-ply thickness at the remaining three comers.

A top closure formed of closure flaps similar to bottom flaps 16 may beprovided if so desired, or the top end may be closed with a paperboardcap 26 as shown in FIG. 5. Also, flaps 16 may be eliminated and thebottom closed with a cap. For the type of product for which thecontainer has found special utility, it is usually transported andmounted on a pallet because of the heavy weight of the contents. Hence,a single-ply bottom closure formed by flaps 16 is all that is requiredfor bottom strength because of the reinforcing effect of the pallet.

In the particular embodiment disclosed in FIGS. 1 through 8, thecontainer is about 41 inches in height and 33 X 34 inches (insidedimensions) in rectangular cross section. However, such dimensions arenot critical and may vary widely. Although any suitable thickness forthe plies may be employed depending upon the material to be packaged,for synthetic rubber blocks the plies are made of conventional doublewall corrugated paperboard comprising two corrugated mediums 27adhesively bonded to an intermediate paperboard liner 28 and to outerliners 29 as can be seen from FIG. 2. A suitable weight of each of thecorrugated mediums is about 26 pounds per thousand square feet, and asuitable weight for each of the liners is about 42 pounds per thousandsquare feet. To enhance strength, the plies are desirably arranged sothat at least two plies have their corrugations run transversely withrespect to each other. The corrugations of the outer ply desirablyextend vertically, the intermediate ply horizontally, and the inner plyvertically. However, the intermediate ply corrugations may extendvertically; and either of the inner or outer ply corrugations or bothmay extend horizontally.

FIGS. 7 and 8 illustrate the method of making the container. Thecontinuous strip which provides inner ply 2 is collapsed to bring panels8 and 3 together; and form abutment joint 13. Adhesive is applied to theinner faces of pads 17 which provide the intermediate ply, and they aresecured to the outer faces of intermediate ply 2 with a hinge connectionline 19 of each pad 17 in substantial alignment with an integral hingeconnection line or corner 11 of inner ply 2, thus forming a laminatedtwoply construction. Then the two-ply construction is collapsed from theposition shown in FIG. 7 to the position shown in FIG. 8 wherein thehinge connection corner 11 between panels 7 and 8 and the hingeconnection corner 11 between panels 4 and 6 are on opposite faces of thetwo-ply construction. Outer pads 22 with adhesive on their inside facesare then adhesively united to the thus folded two-ply structure with anintegral corner 23 of each pad in substantial alignment with a corner 11ofinner ply 2 over the space 21' between adjacent pads 17. The unitedthree plies are then run through a compressor to firmly bond all theplies together, thus forming the described container when the structureis set up from collapsed state.

FIGS. 9 through 13 illustrate a modified construction which issubstantially the same as that described except that the intermediateply 31 is formed of a continuous strip, and the abutment joint of theinner ply is at a comer. Intermediate ply 31 comprises four hingedlyconnected full wall panels 32, 33. 34 and 35 having hingedly connectedclosure flaps 36 at top and bottom. Inner ply 37 also comprises fourfull wall panels 38, 39, 41 and 42. In making the container, adhesive isapplied to the inside face of intermediate ply 31, and end panels 38 and42 of inner ply 37 are turned inwardly along end score lines 43 andsecured to panels 33 and 34 of intermediate ply 31, with their end edges44 in substantial alignment with the central score line 46 ,ofintermediate ply 31. Then end panels 32 and 35 of intermediate ply 31are turned inwardly and secured to the outside faces of panels 39 and 41of the inner ply, thus forming a two-ply construction.

With adhesive applied to two L-shaped pads 47 of the characterpreviously described, they are secured to the outside faces ofintermediate ply 31 with the panels of one pad 47 overlying panels 32and 35 of intermediate ply 31, and the panels of the other pad 47overlying panels 33 and 34 of such intermediate ply. The three-plystructure is then passed through a compressor, as previously related.

As can be seen from FIG. 14, the described construction also results inat least two-ply thickness at each corner. Also, all gaps and jointsbetween adjacent wall panels at each corner are covered by an integralcorner of a contiguous ply. Since the modification thus described has aplurality of pads forming only the outside ply, the two pads of theintermediate ply of FIGS. 1 through 8 are eliminated, it has themanufacturing advantage of enabling the structure to be assembled fasterin the box plant.

In the described modification, closure flaps 36 are provided at both topand bottom but caps of the type shown in FIG. 5 may be employed in placeof either set of bottom or top closure flaps. Although in themodification of FIGS. 1 through 8, the closure flaps are on the innerply, they may be provided on the intermediate or outer ply if sodesired, and vice versa with respect to the modification of FIGS. 9through 13.

The principle of construction is applicable to any polygonalcross-sectionally shaped container. FIGS. 15 through 17 illustrateschematically such construction for a hexagonal crosssectionally shapedcontainer. The inner ply comprises a continuous strip of hingedlyconnected panels 51, the end panels of which are in substantial abutmentto provide abutment joint 52.

An intermediate ply is formed of two pads 53 of a strip of threehingedly connected panels 54, the end edges 56 of which are unattachedand extend to a corner of the container. The outer ply also comprises apair of pads 57 similar to pads 53, the end edges 58 of which extend toan integral corner 59 of intermediate pad 53 and are unattached togetherat such comer. Thus a so-called manufacturers joint is not required, andthere is at least two-ply thickness at all comers of the container withgaps between adjacent end edges of adjacent panels of a ply covered byan integral corner of a contiguous ly. p We claim:

1. A multi-ply container having upright comers and walls composed of aplurality of plies laminated together, at least one of said plies beinga continuous strip of integrally connected panels with all adjacentpanels hingedly connected together except at the edges of the endpanels, at least another of said plies comprising a plurality ofseparate pads nonintegral with any of the other components of saidcontainer, each pad having upright end edges and wall panels integrallyconnected along an upright hinge connection line positionedsubstantially in alignment with an upright corner of the container, andthe length of each pad being such that each end edge thereof is locatedat another corner of the container with a space between the end edges ofadjacent pads.

2. The multi-ply container of claim 1 wherein a ply contiguous to saidanother ply comprises adjacent panels integrally connected along anupright hinge connection line closing each of said spaces.

3. The multi-ply container of claim 2 comprising at least three plies afirst of which being an inner ply comprising panels hingedly connectedtogether except at the edges of the end panels thereof, said edges beingunattached and forming substantially an abutment joint, a second of saidplies is an intermediate ply which covers said abutment joint, and athird of said plies is an outer ply which comprises said plurality ofpads.

4. A multi-ply container having upright corners and comprising an innerply, an intermediate ply and an outer ply adhesively bonded together,said inner ply being composed of a plurality of hingedly connected wallpanels the end panels of which have upright facing edges unattached toeach other, said intermediate ply covering said facing edges of saidinner ply and having at at least one comer of the container uprightedges which are unattached to each other, said outer ply including aplurality of wall panels integrally connected along an upright hingeconnection line substantially in alignment with and covering a corner ofthe container, end edges of adjacent panels of said outer ply beingunattached to each other at a corner of the container, and saidcontainer having at least twoply thickness at each corner thereof.

5. The container of claim 4 wherein said intermediate ply comprises aplurality of pads.

6. The container of claim 4 wherein said intermediate ply is acontinuous strip of wall panels the end panels of which are the onesthat have said unattached edges.

7. The container of claim 4 in which the plies are of paperboard, and atleast two of said plies have their corrugations extending transverselywith respect to each other.

8. The container of claim 4 wherein at least one of said plies hashingedly connected closure flaps to provide a closure for the container.

9. A multi-ply container composed of at least three plies adhesivelybonded together and having upright walls and an upright cornerconstruction of two-ply thickness provided by two of the plies, theremaining ply having adjacent end edges unattached to each other at saidcorner.

10. The construction of claim 9 wherein the inner of said plies has endedges substantially in abutment and unattached to each other.

11. A multiply container comprising at least three plies laminatedtogether, a first one of which being an inner ply comprising panelshingedly connected together except at the edges of the end panelsthereof, said edges being unattached and forming substantially anabutment joint, a second of said plies being an intermediate ply whichcovers said abutment joint, and a third of said plies being an outer plycomprising a plurality of pads with each pad having upright end edgesand wall panels integrally connected along an upright hinge connectionline positioned substantially in alignment with an upright corner of thecontainer, the length of each pad being such that each end edge thereofis located at another corner of the container with a space between theend edges of adjacent pads, and a ply contiguous to said pads which formsaid outer ply comprising adjacent panels integrally connected along anupright hinge connection line closing each of said spaces between suchpads.

12. The multi-ply container of claim 11 wherein said intermediate ply isalso comprised of a plurality of said pads.

13. The multi-ply container of claim 11 wherein said joint of said innerply is located between adjacent corners of the container.

14. The multi-ply container of claim 11 wherein said joint of said innerply is located at a corner of the container.

15. The multi-ply container of claim 11 wherein said intermediate plycomprises panels hingedly connected together along integral hingeconnection lines except the end panels the edges of which are unattachedat a corner of the container.

1. A multi-ply container having upright corners and walls composed of aplurality of plies laminated together, at least one of said plies beinga continuous strip of integrally connected panels with all adjacentpanels hingedly connected together except at the edges of the endpanels, at least another of said plies comprising a plurality ofseparate pads nonintegral with any of the other components of saidcontainer, each pad having upright end edges and wall panels integrallyconnected along an upright hinge connection line positionedsubstantially in alignment with an upright corner of the container, andthe length of each pad being such that each end edge thereof is locatedat another corner of the container with a space between the end edges ofadjacent pads.
 2. The multi-ply container of claim 1 wherein a plycontiguous to said another ply comprises adjacent panels integrallyconnected along an upright hinge connection line closing each of saidspaces.
 3. The multi-ply container of claim 2 comprising at least threeplies a first of which being an inner ply comprising panels hingedlyconnected together except at the edges of the end panels thereof, saidedges being unattached and forming substantially an abutment joint, asecond of said plies is an intermediate ply which covers said abutmentjoint, and a third of said plies is an outer ply which comprises saidplurality of pads.
 4. A multi-ply container having upright corners andcomprising an inner ply, an intermediate ply and an outer ply adhesivelybonded together, said inner ply being composed of a plurality ofhingedly connected wall panels the end panels of which have uprightfacing edges unattached to each other, said intermediate ply coveringsaid facing edges of said inner ply and having at at least one corner ofthe container upright edges which are unattached to each other, saidouter ply including a plurality of wall panels integrally connectedalong an upright hinge connection line substantially in alignment withand covering a corner of the container, end edges of adjacent panels ofsaid outer ply being unattached to each other at a corner of thecontainer, and said container having at least two-ply thickness at eachcorner thereof.
 5. The container of claim 4 wherein said intermediateply comprises a plurality of pads.
 6. The container of claim 4 whereinsaid intermediate ply is a continuous strip of wall panels the endpanels of which are the ones that have said unattached edges.
 7. Thecontainer of claim 4 in which the plies are of paperboard, and at leasttwo of said plies have their corrugations extending transversely withrespect to each other.
 8. The container of claim 4 wherein at least oneof said plies has hingedly connected closure flaps to provide a closurefor the container.
 9. A multi-ply container composed of at least threeplies adhesively bonded together and having upright walls and an uprightcorner construction of two-ply thickness provided by two of the plies,the remaining ply having adjacent end edges unattached to each other atsaid corner.
 10. The construction of claim 9 wherein the inner of saidplies has end edges substantially in abutment and unattached to eachother.
 11. A multi-ply container compRising at least three plieslaminated together, a first one of which being an inner ply comprisingpanels hingedly connected together except at the edges of the end panelsthereof, said edges being unattached and forming substantially anabutment joint, a second of said plies being an intermediate ply whichcovers said abutment joint, and a third of said plies being an outer plycomprising a plurality of pads with each pad having upright end edgesand wall panels integrally connected along an upright hinge connectionline positioned substantially in alignment with an upright corner of thecontainer, the length of each pad being such that each end edge thereofis located at another corner of the container with a space between theend edges of adjacent pads, and a ply contiguous to said pads which formsaid outer ply comprising adjacent panels integrally connected along anupright hinge connection line closing each of said spaces between suchpads.
 12. The multi-ply container of claim 11 wherein said intermediateply is also comprised of a plurality of said pads.
 13. The multi-plycontainer of claim 11 wherein said joint of said inner ply is locatedbetween adjacent corners of the container.
 14. The multi-ply containerof claim 11 wherein said joint of said inner ply is located at a cornerof the container.
 15. The multi-ply container of claim 11 wherein saidintermediate ply comprises panels hingedly connected together alongintegral hinge connection lines except the end panels the edges of whichare unattached at a corner of the container.